Shutter for cinematographic apparatus



P. s. mum/n. SHUTTER FOR CINEMATOGRAPHIC APPARATUS.

APPLICATION FILED APR. 7, 1920.

Patented Aug. 23, 1921.

2 SHEETSSHEET L P. S. GAURIAT.

SHUTTER FOR CINEMATOGRAPHIC APPARATUS.

APPLICATION HLED APR. 7. 1 920.

Patented Aug. 23, 1921.

2 SHEETSSHEET 2.

UNITED STATES PATENT OFFICE.

PIERRE SYLVAIN GAURIAT, 01:". PARIS, FRANCE, .A SSIGNOR TO ETABLISSEMENTS CONTINSOUZA (SOCIETE ANONYME), OF PARIS, FRANCE, A FRENCH CORPORA- Specification of Letters Patent.

Patented Aug. 23, 1921.

Application filed April 7, 1920. Serial No. 371,950.

To all whom it may concern: I

Be it known that I, PIERRE SYLVAIN Garr- RIAT, citizen of the French Republic, res1ding at Paris, Department of the Seine, 1n France, and having P. 0. address 9 and 13 Rue des Envierges, in the said city, have invented certain new and useful Improvements in Shutters for Cinematographic Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable.

cylindrical form is mounted on the vanes of a fan or is formed in one piece therewith; it turns in a casing; this casing incloses the lantern of the apparatus.

An essential characteristic of the ventilating shutter device is that it takes up considerably less space than the usual plane shutter placed parallel with the film.

The rotation of the fan driving the shutter at the same time draws in to the center of the casing fresh air which it introduces into the lantern to augment its draft, cool the lamp and by this reason prolong its life. In a modification the truncatedly conical shutter is located not between the film andthe luminous source, but between the film and the object glass. The shutter is placed insuch a manner that its generating line will be parallel to a vertical plane as close as possible to the film. The position of th1s shutter between the window and the object glass fixes the entry and exit of the covering wings in the beam parallel to the long side of the film images.

Figure 1 shows a diagrammatic arrange.- ment with a truncatedly conical shutter.

Fig. 2 is a modified arrangement of shutter.

Fig. 3 is a bot-tom plan view thereof Fig. 4 is a transverse, vertical, sectional view of the shutter and fan.

Fig. 5 is a horizontal sectional view thereof.

Fig. 6 is a vertical sectional view of the clutch forming the driving connection for the fan and shutter.

a Fig. 7 is a sectional view showing the clutch engaged.

F 8 shows the clutch disconnected, and

F igs. 9, 10, 11 and 12 illustrate modified arrangements of mounting the shutter.

The truncated conical shutter is shown at 1, they fan at 2, the fan casing at 3, the illuminating source at 4; and the condenser at 5.

By the rotation of the fan 2, the air drawn in at the center of the fan casing 3 is forced out into the lantern at the periphery of said fan or the exit orifice 6, when said fan is provided with a surrounding inclosed rim or air directing casing 3. This casing 3' is readily moved so that the exit orifice 6 may face any suitable chosen direction.

The cooling of the lamp is also obtained in projection when for any reason it is necessary to stop the movement of the film while continuing the rotation of the fan which drives the shutter and preserves on the screen the same luminous pro ection.

The transit on from moving projection to intensity as in moving silent fixed projection and vice versa is ob-' tained (or can be obtained) by the following, device described by way of example: Figs. 6, 7 and 8.

On a shaft 7 driven either directly or indirectly by hand or by a motor are two toothed wheels with a properly chosen number of teeth, one 8, fixed on the shaft and carrying a pawl 9v with a spring pin 10, the other, 11, fixed to a ratchet 12 loose on 8.

The wheel 8 drives by intermediaries the fan which drives the shutter, the shaft 7 through gear 11 drives the mechanism for.

moving the film.

By the rotation in the direction indicated by the arrow the pawl drives the ratchet and the wheel 11. r

For fixed projection it suflices to turn in the opposite direction to the arrow, the pawl then mounts on the incline of the ratchet,

the spring pin being forced in so as to leave the notch 13 and engage in the notch 14 as soon as it has passed the projection which separates them, giving thus to the pawl a movement such that it is maintained in the upper part, Fig. 8, in a position which envelops without touching the external diameter of the ratchet.

The wheel 11 is thus disconnected and the noise which the pawl would make in passing over the ratchet teeth is thus suppressed.

The transition to moving projection is obtained by rotating in the normal direction and pushing relatively to the movement of the boss of the pawl a finger 15 which causes it to return to the lower position held by its spring pin in the notch 13.

By properly choosing the number of the teeth of the ratchet and the driving gears, the lowering of the shutter relatively to the eclipsing of the image is always secured.

An automatic safety shutter 16, Fig. 1, op-,

erated by a regulator acting in the two directions of rotation masks the projection window when the speed of the members of the apparatus falls below the normal.

In the modification shown in Figs. 9, 10, 11 and 12, the form of the shutter is always that of a truncated cone. This shutter is shown at 1 and it will be seen that it is located between the window 2 through which the film passes and the object glass .3. The luminous source and the condenser are placed on the other side of this window.

The axis of the frustum is located in the horizontal plane passing through the large axis of the window and the axis of the object glass.

This'arrangement has the advantage of covering and uncovering the luminous beam following a direction practically parallel with the long side of the image, the entry and exit of the covering wings taking place in the shortest possible time.

The new position has moreover the advantage of cutting the luminous beam at one of its smallest cross-sections. The shutter in the modification possesses also as a feature that of covering the beam while mov' ing in the same direction as the film; this has an influence favorable to the suppres sion of wire drawing for a minimum covering of the beam.

In Figs. 11 and 12 are shown in broken lines the different positions of the covering wing at the moment of its entry and exit from the luminous beam. Fig. 11 shows the case of a disk shutter and Fig. 12 the case of a truncatedly conical shutter. To reduce the time of the operations of opening and closing of the shutter there is provided a single wing so as to increase its speed.

laims:

1. In a cooling arrangement for the lamps of projecting apparatus, the combination with a rotatable, truncated, conical shutter, of a fan associated with said shutter, said fan being constructed to direct the cooling air through its wholeperiphery, and means for rotating said shutter and fan simultaneously and also causing the feeding of the film past said shutter during the operation of the apparatus.

2. In a cooling arrangement for the lamps of projecting apparatus, the combination with a rotatable, truncated, conical shutter, of a fan associated with said shutter, said fan being constructed to direct the cooling air through its whole periphery, means for rotating said shutter and fan simultaneously and causing, the feeding of the film past said shutter during the operation of the apparatus, and a clutch whereby the rotation of the shutter and fan may be continued after the stopping of the film.

In testimony whereof I affix my signature.

PIERRE SYLVAIN GAURIAT. 

